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Hydrus
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Ursa major constellation illustration art. (Big Dipper) stars, space, night sky)
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Greek:
“Water Snake”
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Hydrus

astronomy
Written by
Erik Gregersen
Erik Gregersen is a senior editor at Encyclopaedia Britannica, specializing in the physical sciences and technology. Before joining Britannica in 2007, he worked at the University of Chicago Press on the...
Erik Gregersen
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Britannica Editors
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree....
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History

Hydrus, constellation in the southern sky at about 2 hours right ascension and 70° south in declination. Its brightest star is Beta Hydri, with a magnitude of 2.8. This constellation was invented by Pieter Dircksz Keyser, a navigator who joined the first Dutch expedition to the East Indies in 1595 and who added 12 new constellations in the southern skies. The much larger constellation Hydra represents a female water snake, whereas Hydrus is the male.

Erik Gregersen
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